Magnetically shielded structure with adjustable cover member supporting a magnetron



June 13, 1967 A R JR" E 3,325,678

MAGNETIGALLY SHIELDED STRUCTURE WITH ADJUSTABLE COVER MEMBER SUPPORTING A MAGNETRON Filed June 2, 1966 2 Sheets-Sheet 1 2 VII In villi,

INVENTORS: GEORGE A. KRUG JR. TRUMAN P. CURTIS,

TH IR ATTORNEY.

June 13, 1967 G. A. KRUG. JR.. ETAL 3,325,678

MAGNETICALLY SHIELDED STRUCTURE WITH ADJUSTABLE COVER MEMBER SUPPORTING A MAGNE'I'RON Filed June 2. 1966 2 Sheets-Sheet z INVENTORS! GEORGE A. KRUGJR.

TRUMAN P. CURTIS,

T IR ATTORNEY.

United States Patent 3,325,678 MAGNETIICALLY SHIELDED STRUCTURE WITH ADJUSTABLE COVER MEMBER SUPPORTING A MAGNETRON George A. Krug, In, and Truman P. Curtis, Schenectady,

N.Y., assignors to General Electric Company, a corporation of New York Filed June 2, 1966, Ser. No. 554,789 9 Claims. (Cl. 315-3971) ABSTRACT OF THE DISCLOSURE A shielded magnetron assembly which includes an enclosure or housing of a magnetic material. A pair of oppositely disposed magnets are attached to surfaces within the housing and include in the defined space therebetween a voltage tunable magnetron. The magnetic material housing is utilized as the return path for magnetic flux between the magnets and to magnetically shield the internal apparatus. A pair of spaced window opening and cover assemblies in the housing supports a circuit frame including a magnetron tube therein between the magnets. A combination sliding-universal type connection between each cover and the frame permits the covers to be 'slidable over their openings to accurately magnetically align the magnetron tube with respect to the magnets.

This invention relates to an improved shielded magnetron unit assembly, and more particularly to a voltage tunable magnetron unit assembly or package and its associated circuitry incorported within an R-F and a magnetically shielded housing. This application is a continuation-in-part application of copending application Ser. No. 441,438, filed Mar. 22, 1965, now abandoned and assigned to the same assignee as the present invention.

Technological improvements and advancements in electronic apparatus or equipment to which voltage tunable magnetrons are particularly applicable require a voltage tunable magnetron assembly which is more compact, and of a regular or near geometrical configuration. In addition, and more importantly, electronic equipment to which voltage tunable magnetrons are applicable has become more complex as well as compact, so that a number of electronic devices occupy the same module or are in close association with one another. In such apparatus, where one of the electronic devices, for example a magnetron, employs a permanent magnet, the magnetic lines of force may seriously affect other electronic devices, or the magnetron may be affected by magnetic fields of adjacent devices. Therefore, a considerable distance is maintained between the magnetron and related electronic equipment, a practice which contributes to larger and more bulky apparatus. There are also practical space limitations associated with the described apparatus so that while spacing from a magnetic source weakens magnetic force, the presence of weak lines of force remain inherently troublesome not only to other apparatus but also to the magnetron itself when generated from other sources. To further complicate the mentioned problems, many prior magnetron assemblies also include R-F power leaks which are undesirable in most applications.

Accordingly, it is an object of this invention to provide an improved shielded voltage tunable magnetron assembly.

It is another object of this invention to provide an improved shielded voltage tunable magnetron package configuration of a compact and regular geometrical configuration.

it is yet another object of this invention to provide an Patented June 13, 1967 improved R-F and magnetically shielded voltage tunable magnetron.

It is another object of this invention to provide an improved adjusting arrangement to adjust the position of an electron discharge device between magnets in a magnetically shielded housing.

It is another object of this invention to provide an improved adjusting arrangement to adjust the position of a voltage tunable magnetron and its associated circuit between magnets in a magnetically shielded housing.

It is yet another object of this invention to provide a relatively rectangular fully magnetically shielded voltage tunable magnetron having enclosed oppositely disposed magnets and an improved intermediate magnetron adjusting means.

Briefly described, this invention in one of its preferred forms includes an enclosure or housing of a magnetic material. A pair of oppositely disposed magnets are attached to surfaces within the housing and include in the defined space therebetween a voltage tunable magnetron. The magnetic material housing is utilized as the return path for magnetic flux between the magnets and to magnetically shield the internal apparatus. A pair of spaced window opening and cover assemblies in the housing supports a circuit frame including a magnetron tube therein between the magnets. A combination sliding-universa1 type connection between each cover and the frame per mits the covers to be slidable over their openings to accurately magnetically align the magnetron tube with respect to the magnets.

This invention will be better understood when taken in connection with the following description and the drawings in which FIG. 1 is a side elevational and sectional view of a preferred embodiment of this invention;

FIG. 2 is an exploded view of the magnetron tube and supporting covers of FIG. 1;

FIG. 3 is an exploded view of a modification of the adjustable supporting means of FIG. 2;

FIG. 4 illustrates the adjustable retention means of this invention as applied to a cylindrical housing;

FIG. 5 illustrates one preferred housing configuration of this invention.

Referring now to FIGS. 1 and 2, a side cross sectional and elevational view of this invention is illustrated to present the interrelationship and assembly of the individual parts which make up the entire unit. In FIG. 1 housing 11 may be of any of the configurations of for example those illustrated in FIGS. 3, 4 and 5 or combinations thereof. Housing 11 includes a pair of oppositely disposed magnets 12 and 13, each of which is butt-joined to the interior surfaces of endplates 14 and 15 by a suitable solder or braze, for example silver soldering. Best results are usually obtained in a voltage tunable magnetron assembly when the magnets are of an'elongated circular cross section design as illustrated in the present invention by magnets 12 and 13 in one form being of cylindrical shape. The magnetic field from a circular magnet is generally optimum for a magnetron tube which is also of a cylindrical configuration. Other tapered or frustoconical shaped magnets as well as magnets of cross sections other than circular may also be employed in this invention.

Housing 11 includes oppositely disposed wall portions 16 and 17 each of which is provided with apertures or window openings 18 and 19 respectively. Apertures 18 and 19 are in alignment with a defined space 20 between magnets 12 and 13, i.e., their common axis passes transversely through the defined space 20.

An electron discharge device, for example a voltage tunable magnetron and circuit assembly 21 is retained within the defined space 20 so that the voltage tunable magnetron 22 (FIG. 2) is in accurate magnetic alignment with the magnets 12 and 13 for optimum output characteristics. Adjustable retention means are provided for the magnetron assembly 21 in the form of cover assemblies 23 and 24 associated with apertures 18 and 19 respectively.

The retaining and adjusting means is similar for each cover assembly 23 and 24 and a description of one suffices for the other. Cover assembly 23 for example comprises a plate 25 which includes a small rectangular opening 26 therethrough. To further define the opening 26, a pair of channel or angle members 27 of a nonmagnetic material such as for example stainless steel or aluminum'are suitably soldered or brazed to opposed sides of the opening 26 in plate 25. Angle members 27 are also oppositely arranged so that they present protruding shelf portions 28 extending perpendicularly from the inner face of plate 25. Cover assembly 24 also includes an opening 26', angles 27' and shelf surfaces 28, all mounted in the same manner as that described for cover assembly 23. Angle members 27 and 27 are of a nonmagnetic material because their projecting portions are in the proximity of the magnetic field of magnets 12 and 13.

Each of the apparatus 18 and 19 is defined Within its respective wall portion member 16 and 17 by suitable indentions or recesses 29 and 30 in wall portions 16 and 17 respectively. The indentions 29 and 30 are of sufficient depth to receive the thickness of plate members 25 and 25 therein for flush mounting with the outer surfaces of housing 11. In addition, each indention 29 and 30 is larger in length and width dimensions than the respective plate members 25 and 25'. The angle members 27 defining protruding shelves 28 are positioned in parallel spaced apart relationship on cover plates 25 and 25 so that they are easily passed into or through their respective apertures 18 and 19, leaving sufficient distance for vertical adjustment of the cover assemblies 23 and 24 with respect to housing 11. In addition, the angle members 27 are of a length which will also permit easy lateral insertion into or through the respective openings 18 and 19 and at the same time provide for some lateral movement. The oversize opening-undersize cover angle relationship provides full linear or curvilinear adjustment of the covers assemblies 23 and 24 in the housing 11.

Referring now to FIG. 2, the tube circuit assembly 21 is illustrated as including a boxlike frame 31 in which a magnetron tube 22 is suitably concentrically positioned along an axis transverse to the plane of the box frame 31 and in a central defined recess 32. Box frame 31 also includes intermediate and projecting side portions 33 and 34 oppositely disposed along the longer sides of box frame 31. The tube 22 is positioned in box frame 31 between projections 33 and 34. Projections 33 and 34 are conveniently of a similar size and configuration as apertures 18 and 19 and may project therein. The projecting portions 33 and 34 are snugly engaged or clasped by the shelf portions 27 and 27' of cover members 23 and 24 respectively, so that tube assembly 21 is supported between the two cover members and is releasably secured or restrained from movement relative thereto.

First and second spaced cover assemblies 23 and 24 retain and support the circuit assembly 21 therebetween as illustrated in FIG. 1, and, at the same time provide for adjustable positioning of assembly 21 relative to the housing 11 omnidirectionally. For example, either or both of the cover assemblies 23 and 24 may slide within the indentions 29 and 30 pivotally or universally with respect to assembly 21. This sliding motion may be either in the vertical or horizontal direction or both, rectilinear or curvilinear. Also, one cover assembly may be slidably adjusted relative to the other.

Simultaneous motion of each cover assembly may raise, lower or shift the frame 31 in opposite side directions or provide combined vertical and horizontal adjustment without change of relationship between frame 30 and shelves 27. Also, simultaneous rotation of the cover assemblies 23 and 24 will provide rotational movement of frame 30 within limitations of apertures 18 and 19.

By moving one cover assembly with respect to the other the angular position of frame 31 with respect to the defined space 20 may be changed in both the vertical and horizontal planes because of the clasping action of the shelves and shape of the projections 33 and 34 permit a partial rotational or angular movement of frame 31 in shelves 26 in either the horizontal or vertical direction. Also frame 31 may be laterally adjustable as illustrated in FIG. 1 by movement in opposite directions further into or out of engagement with either pair of shelves on each plate 25 and 25'. Overall adjustment includes relative motion between the circuit 21 and covers 23 and 24, which may be described as limited pivotal motion, and relative motion between the covers 23 and 24 and hous ing 11. The relative motion between the circuit 21 and covers 23 and 24 will permit only a very limited degree of rotation of the circuit, i.e., due to clearances between the circuit 21 and the shelf members 23 and 24, or flexibility of the shelf members. Rotational movement is provided by slidingly rotating a cover in its indentation which therefore provides a pivot-like motion of circuit with a limited amount of rotation. Sliding of a cover member linearly in its indentation changes the pivot position. Sliding of the circuit to a greater depth between the shelf portions also changes the pivot point. One analogy or modification would be the connection of the circuit 21 to each cover 23 and 24 by means of a releasable or snapapart ball socket joint or universal joint which are adapted, however, to provide some rotation of the circuit 21 from outside housing 11 by rotation of a cover. The ball portion may be suitably attached to the circuit and the cup attached to the cover. Additional adjustment'is provided by having the mentioned joints axially adjustable for example by suitable telescoping means so that the axial position of the circuit 21 between covers 23 and 24 may be adjusted. The overall adjusting action is in a sense omnidirectional or pivotal where the pivot itself or pivot base is movable.

Where the projecting portions 33 and 34 extend a considerable distance from assembly 21 or are equipped with suitable extenders, or are originally formed to extend further, the shelf members 27 may be deleted and the projections 33 and 34 may then simply engage the edges of openings 26 and 26'. It is not necessary that openings 26 and 26' be of similar configuration to projections or bosses 33 and 34. It is only necessary that sufiicient clearance be maintained so that a wobble or universal action of the frame is permitted with respect to the housing 11 or apertures 26 and 26'.

In the final assembly of the unit of this invention, housing 11, with magnets 12 and 13 in place, is maintained in a fixed position while the assembly 21 is adjusted by means of cover assemblies 23 and 24 so that the magnetic lines of force of the magnets pass in the optimum direction through magnetron tube 22. Thereafter, cover assemblies 23 and 24 may be joined to housing 11 by mechanical means or bonding means. In one preferred form of this invention the cover means are suitably soldered or brazed within their indentions 29 and 30 to fixedly position the circuit frame 31 with respect to the magnets 12 and 13. The solder metal is also caused to flow between the shelf portions 27 and projections 33 and 34 to attach frame 31 to cover members 23 and 24. An electrically conductive potting compound 35 such as a silver filled epoxy or rubber is employed to fill the openings 26 and 26.

The degree of adjustment for these voltage tunable magnetrons is very small so that only small clearances are needed. However, the adjustment must be quite precise for optimum results and considerable care is exercised. The foregoing arrangement is particularly advantageous because the assembly 21 is not connected to or supported from the magnets 12 and 13, and adjustments are made on the assembly 21 externally of the housing and relative to the housing. It is therefore not necessary to adjust the magnets with respect to the assembly 21. The method of assembly and adjustment is highly desirable where the overall package is of a reduced size and clearances minimal. It is expedient to have the output connector 36 of the circuit assembly extend through one of the apertures 18 or 19. The output connector in some instances may serve as one of the projections or bosses on the frame assembly for adjustable retention purposes.

For some purposes less adjustment may suflice and therefore one cover assembly may be fixed to the housing yet permitting pivotal movement of frame 31 thereabout. Movement of the other cover assembly is utilized for adjusting purposes within the imposed limits of a fixed pivot. However, a pivot motion must be established at each cover assembly. For simultaneous pivoting action of the frame 31 in each cover assembly at least one pivot point or base must be adjustable in a direction other than along the axis intersecting each pivot.

FIG. 3 discloses a modification of the adjusting and supporting means of this invention where the overall package dimensions are further reduced. For example, in FIG. 1 the apertures 18 and 19 may be of sufiicient size to permit insertion therethrough of the frame assembly 21. With further reduction of the housing 11 to a more square cross sectional configuration where the circuit assembly 21 must also approach a square configuration laterally, the supporting electron apparatus usually contained in recesses 37 and 38 of frame 31 (FIG. 2) is repositioned to spaces above and below frame 31. Consequently an aperture for insertion of the frame 31 into the housing may constitute most of a wall portion of a given housing.

In FIG. 3 such a small housing is indicated as 39. A circuit assembly 40 is positioned in the housing with opposed bosses 41 and 42 projecting toward defined apertures 43 and 44 (not shown) in the housing walls 45 and 46. In one form, assembly 40 is positioned in housing 39 and thereafter the last wall 45 is joined to housing 39. Ferrule type members 47 and 48 are utilized, similarly to the cover members of FIG. 1, to adjustably retain circuit assembly 40 in housing 39. Since the ferrule members are similar a description of one will suffice. A ferrule member 47 includes a flange portion 49 and a projecting tubular or barrel-like portion 50. Tubular portion 50 is smaller than aperture 43 and passes through aperture 43 to receive boss 41 therein. Tubular portion 50 has inside dimensions larger than boss 41 so that boss 41 may move omnidirectionally therein, while tubular portion 5t), with its flange 49 adjacent wall 45, may slide about within aperture 43. Manipulation of each ferrule 47 and 48 or one with respect to the other, in the manner of the cover members 23 and 24 of FIG. 1, provides proper adjustment of the magnetron, in circuit assembly 40, with respect to the magnets in housing 39.

FIG. 4 discloses the supporting and adjusting means of this invention as applied to a cylindrical housing 51. In FIG. 4a number of support elements such as rods 52 are attached to a magnetron tube circuit assembly 53 and extend through enlarged apertures 54 in housing 51. Preferably three such apertures are desirable and spaced equidistantly about the periphery of the housing. Curved washer or cover members 55 having apertures 56 therethrough of a larger diameter than rods 52 are fitted over rods 52 and coincide with the curvature of housing 51. Sliding movement of one or more of Washers 55 with respect to each other or with respect to housing 51 provides similar omnidirectional adjustment of circuit assembly 53 as described with respect to FIG. 1.

FIG. 5 illustrates one preferred embodiment of this invention and may be described as a front view of FIG. 1. In FIG. 5 the flattened rectangular configuration housing 57 provides larger rectangular oppositely disposed front and back surfaces 48 and 49 with curved end panels 60 and 61. End panels 60 and 61 are curved in conformity with the curvature of cylindrical magnets such as 12 and 13 but may be straight to provide a rectangular configuration. Suitable reduction or changes in dimensions may provide a housing 57 of a cube or rectangular parallelepiped configuration wherein the output connector may be adapted to protrude through any wall. For example, the output connector of FIG. 1 may project through any side wall or end wall such as a curved or straight end wall 60 of FIG. 5. FIG. 1 may also be illustrative of an output connector extending through a narrow end wall.

In each of the described embodiments a circuit assembly comprises a frame member and a magnetron tube supported therein. In each instance, the frame functions as the circuit assembly for the tube 22. Both the circuit assembly 21 and the tube 22 may be functionally similar to a circuit and tube device as disclosed in US. Patents 3,020,445 Weinstein and 3,020,446 Bessarab, assigned to the same assignee as the present invention. Tube device 22 is electrically operative by means of control leads (not shown) which are connected to electrode contact buttons 62, 63 and 64 (FIG. 2) and pass through a typical housing 11 (FIG. 1) by means of lead-in capacitor connectors 65, 66 and 67. Power output from tube 22 is coupled from circuit assembly 31 in the usual manner, for example by a probe coupler, through output connection 36.

By means of this invention a fully magnetically shielded housing is provided for a specific voltage tunable magnetron structure which employs separate oppositely positioned magnets 12 and 13 as distinct from the E and C magnet type, and serves as the magnetic return path. The thickness of the endplates and housing is chosen to be sufiicient to carry the flux density and be effective as shielding.

Because the entire housing including the covers is of a coextensive magnetic material R-F leakage is reduced to a minimum. Full R-F shielding is obtained by the use of lead-in capacitor connections 65, '66 and 67 and the electrically conductive potting material 35 in openings 26 and 26. Operative tests indicate R-F shielding substantially improved over shielding obtained by enclosing known B and C magnet types of voltage tunable magnetrons in a separate shielding enclosure.

This invention provides a small compact package assembly which may have general dimensions in one form of. less than about 4 inches length, 3 inches width, and 1.5 inches thickness. Other forms of this invention may include circular or cylindrical housings. The flattened rectangular configuration greatly facilitates application to other geometrical or compact modules, while at the same time simplifying the shielding problem. In most instances this invention eliminates the need of a separate shielding box structure because the unit is also protected from stray magnetic fields of other nearby devices.

This invention also provides means to insert and withdraw the magnetron and circuit assembly from the face of the housing without disturbing the magnets and without necessity for disconnecting supporting structure from the magnet. Together with ease of insertion and withdrawal, the improved supporting means provides an interrelated method of fully adjusting the magnetron tubein an omnidirectional manner with respect to the magnets.

' Other securing means providing the adjustability function may be used in lieu of the angles 26 or ferrules 47 and 48, or in conjunction therewith. The degree of movement for adjustability need only be very small so that releasable securing means may be employed in lieu of soldering or brazing angles 26 and ferrules 47 and 48 to their respective circuits. Furthermore, whereas any convenient number of adjustable retention means may be employed, a minimum of two is satisfactory. Even with two means, one may be of a different kind than the other. For example one means may be of a ball socket or other equivalent universal-like joint with or without the base of the joint or pivot movable.

While this invention has been described with reference to particular and exemplary embodiments thereof, it is to be understood that numerous changes can be made by those skilled in the art without actually departing from the invention as disclosed, and it is intended that the appended claims include all such equivalent variations as come within the true spirit and scope of the foregoing disclosure.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A magnetically shielded magnetron package unit comprising in combination,

(a) a magnetic sheet metal housing,

(b) a pair of oppositely disposed magnets in said housing, attached thereto and defining a space between poles thereof,

(c) said housing having an aperture therein in communication with said magnetic space,

(d) a magnetron tube and circuit assembly in said housing,

(e) means to support said magnetron tube and circuit assembly in said space solely from said housing, said means comprising (1) a first supporting member engaging said housing and said circuit and providing a pivot for pivotal motion of said circuit assembly about said pivot,

(2) a second supporting member spaced from said first supporting member and engaging said housing and said circuit to provide a pivot for pivotal motion of said circuit assembly about said pivot,

(3) said second supporting member positioned adjacent said aperture for motion thereover to change its pivot point for additional adjustment of said circuit assembly with respect to said magnets,

(4) and adjoining means fixedly joining said second supporting member to said housing,

(f) said housing serving as a magnetic shielding means for said magnetron and as a return flux path for said magnets.

2. The invention as recited in claim 1 wherein an aperture is provided for each of said supporting means and each pivot is fully adjustable with respect to the other pivot.

3'. The invention as recited in claim 2 wherein said housing is of a rectangular configuration.

4. The invention as recited in claim 2 wherein said housing includes a cylindrical configuration.

5. The invention as recited in claim 2 wherein each said support means comprise a member engaging said housing and extending through said aperture to releasably secure a projecting boss on said circuit.

6. A voltage tunable magnetron assembly comprising in combination,

(a) a hollow housing of a magnetic material,

(b) said housing having a pair of spaced wall portions defining a relatively fiat rectangular housing,

() said wall portions having apertures therein concentrically through said housing,

(d) a pair of oppositely positioned spaced apart permanent magnets in said housing extending generally parallel to said front and back faces in said housing and defining a magnetic gap therebetween,

(e) an individual magnetic material cover member for each of said apertures,

(f) a magnetron circuit and a magnetron tube positioned in said housing in said gap and between said cover members with an output connector extending through one of said openings,

(g) releas-ably securing means on each said cover members adapted to engage and support said magnetron 8 circuit and said magnetron tube in pivotal relationship so that said covers may be slidably positioned on said housing to secure said magnetron circuit and said magnetron in alignment with said magnets,

(h) and bonding means joining said covers to said housing.

7. The invention as recited in claim 6 wherein the output connector of said circuit assembly projects through one of the faces other than said front and back faces.

8. A voltage turnable magnetron assembly comprising in combination,

(a) a hollow housing of magnetic material,

(b) said housing having a pair of spaced wall portions defining a relatively flat housing,

(c) said portions having apertures therein concentrically through said housing,

(d) a pair of oppositely positioned spaced apart permanent magnets in said housing extending generally parallel to said front and back faces in said housing and defining a magnetic gap therebetween,

(e) an individual magnetic material cover member for each of said apertures,

(f) a magnetron circuit and magnetron tube positioned in said gap in said housing between said cover members,

(g) one of said cover members defining an opening therethrough,

(h) said magnetron having a radio frequency output projecting through said cover member opening,

(i) a portion of said magnetron circuit being adjacent the other of said cover member's,

(j) means on said cover members adapted to engage and support said magnetron circuit and magnetron tube in pivotal relationship so that said covers may be slidably positioned on said housing to secure said magnetron circuit and magnetron tube in alignment with said magnets,

(k) and bonding means joining said cover members to said housing and said magnetron circuit to said cover members,

(1) and an electrically conductive potting material sealing said openings in said cover members to provide R-F shielding.

9. A voltage tunable magnetron assembly comprising in combination,

(a) a generally rectangular in Y (b) said housing having a pair of spaced apart parallel front and back faces having a dimension substantially larger than the spaced apart dimension therebetween,

(c) said front and back faces each having an aperture therethrough in concentric relationship to each other,

(d) a pair of oppositely disposed spaced apart permanent magnet members in said housing and attached thereto to depend interiorly of said housing parallel to said front and back faces with the spacing therebetween in alignment with said apertures,

(e) magnetic material cover members for each of said apertures adapted to be secured to said housing,

(f) a magnetron tube and magnetron circuit device having a combined dimension smaller than said aperture to be positioned within said housing through said aperture and between said magnets,

(g) shelf means on said cover members adapted to adjustably pivotally secure said magnetron circuit to maintain said circuit and tube between said covers and in spaced relationship to said magnets,

(h) one of said cover members having an opening therethrough so that a radio frequency couple on said circuit projects through said opening,

(i) and means to slidably adjust said window cover members adjacent to and in the plane of said front and back faces to accurately align said magnetron frame and magnetron tube device within said housing etween said magnets,

magnetic sheet metal hous- (j) at least three lead-in capacitor connections in said housing to connect electrical leads to said magnetron unit,

(k) and an electrically conductive sealing compound in said openings to provide R-F shielding,

(l) and lead-in capacitor connections in said housing to connect electrical leads to said magnetron tube.

References Cited UNITED STATES PATENTS 2,468,576 4/ 1949 Teare 315-39.7]

5 HERMAN KARL SAALBACH, Primary Examiner.

S. CHATMON, JR., Assistant Examiner. 

1. A MAGNETICALLY SHIELDED MAGNETRON PACKAGE UNIT COMPRISING IN COMBINATION, (A) A MAGNETIC SHEET METAL HOUSING, (B) A PAIR OF OPPOSITELY DISPOSED MAGNETS IN SAID HOUSING, ATTACHED THERETO AND DEFINING A SPACE BETWEEN POLES THEREOF, (C) SAID HOUSING HAVING AN APERTURE THEREIN IN COMMUNICATION WITH SAID MAGNETIC SPACE, (D) A MAGNETRON TUBE AND CIRCUIT ASSEMBLY IN SAID HOUSING, (E) MEANS TO SUPPORT SAID MAGNETRON TUBE AND CIRCUIT ASSEMBLY IN SAID SPACE SOLELY FROM SAID HOUSING, SAID MEANS COMPRISING (1) A FIRST SUPPORTING MEMBER ENGAGING SAID HOUSING AND SAID CIRCUIT AND PROVIDING A PIVOT FOR PIVOTAL MOTION OF SAID CIRCUIT ASSEMBLY ABOUT SAID PIVOT, (2) A SECOND SUPPORTING MEMBER SPACED FROM SAID FIRST SUPPORTING MEMBER AND ENGAGING SAID HOUSING AND SAID CIRCUIT TO PROVIDE A PIVOT FOR PIVOTAL MOTION OF SAID CIRCUIT ASSEMBLY ABOUT SAID PIVOT, (3) SAID SECOND SUPPORTING MEMBER POSITIONED AD- 